It is known for a core made of ferromagnetic material and serving as an antenna rod to be inserted in a housing and for the wire then to be wound around the housing. The disadvantage of this solution is that the wire and core are separated from one another by the interposed housing, which, owing to scatter losses, leads to reduced efficiency. In addition, different core shapes require the use of differently shaped housings.
It is also known for the wire to be fixed with adhesive tape or similar, and for the core with wire wound around it then to be secured in a housing. The disadvantage here is that the automatic application of the adhesive tape can be achieved only with great complexity, which involves high unit costs, especially in the case of mass production.
DE 198 128 36 A1 shows an inductive miniature component for SMD assembly, with a one-part massive core made of poorly electrically conductive material, in particular ferrite material, and with at least one coil winding disposed around the core. On at least one of its ends, the core has a coil-free section, which may take the form of a rectangular flange and on which a coupling plug made of the same material is integrally formed. Wound onto the coupling plug multiple times is one end of the winding. In the region of the coupling plug, the underside of the coil windings is provided with a tinning coat.
WO 2005/062316 A2 and WO 2005/045992 A2 relate to directionally-independent, flat antennas of miniature design.
Since the direct application of windings to ferrite material is regarded as difficult from the manufacturing viewpoint, a flat winding body in plastic is provided in WO 2005/062316 A2 for an inductive miniature component with three coil windings located perpendicularly to one another. A flat ferrite core in inserted into the winding body.
WO 2005/045992 A2 also relates to an inductive miniature component equipped with three coil windings located perpendicularly to one another. The coil windings are applied to a flat winding body, which is made at least in part of ferrite material and which is provided on its top face and bottom face with guiding elements for directing the third coil winding. Further provided is a coil plate with corners or projections around which the ends of the third coil winding are wound.
The devices from WO 2005/045992 and WO 2005/062316 are specially matched to the geometry of antennas with three coil windings located perpendicularly to one another and of flat design. For rod-shaped cores, for example, the solutions described in these two documents are unsuitable, which severely restricts their application range.